Pressure control for automatic pumps



Oct. 6, 1931. 1 PERSONS 1,826,089

PRESSURE CONTROL FOR AUTOMATIC PUMPS Filed Aug. 5 192 [72 0972 Z37."Lawrence M P62150723.

4, LAW-1M gig??? Patented Oct. 6, 1931 UNITED.

PATENT OFF-ICE LAWRENCE M. PERSONS, OF CHICAGO, ILLINOIS, A SSIG-NOB TOCOOK ELECTRIC COM- PANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOISPRESSURE CONTROL FOR AUTOMATIC PUMPC Application filed August 5, 1923.Serial No. 127,253.

M invention relates to pumping apparatus for fluid supply systems. Anobject of my invention is to provide pumping apparatus having animproved type- 5 of control capable of wide application to fluid supplysystems for controlling the supply of fluid fed bythe pump.

In fluid supply systems, particularly those 'employed to feed liquidfuel, say, to oil 19 burners used for heating purposes, or the like, theoil is generally pumped from a storage tank, such as may be installed onthe outside of the building, to a supply tank located in the building oradjacent to the 5 burner for the purpose of minimizing the amount of oilnecessarily retained within the building near the burner, and from whichtank the oil flows to the burner. It is obvious that some means ofautomatic operation is 20 desirablefor the pumping apparatus, so that aconstant supply will be available for feeding to the burner from thesupply tank. Considerable attention has been given to such I anautomatic control because there is a possibility that it will functionto pump the entire contents from the storage tank into the I building inthe event a leak occurs, or in the eventa siphoning action takes placeafter the system is stopped. On the other hand, so there is a tendencyto minimize the cost of-oil burner installations, with a consequenttendency to eliminate control apparatus if pos= the switch; and

sible.

One of the objects of my invention is to provide an improved simple andinexpensive form ofcontrohwhich isapractical and may be associated withany type of pump in a fluid supply system, and which embodies all theelements of safety, as well as protects against a siphonic action. ofthe .fluid when the pump is stopped. Besides afiording greater safetyand protection, the control eliminates/ unnecessary piping such 'as anoverflow from the pump and may be embodied in a tank located anywhere inthe system. While it is desirable to associate the pump with the tank,obviously the pump 7 and tank may be iprovided separately and eachlocated at di erent points in theisys- 50 tem. v

on line 4-4 0 Fig A more specific object of the invention is to providemeans for starting and stopping the pump, which means is controlled bythe volume or pressure of fluid in the tank, and,

to associate therewith, an air vent operated or by the pressure elementto vent air into the tank, thereby breaking any siphonic action whichthe fluid may have when flowing therefrominto the delivery pipe. .Inorder to apprise those skilled in the art how to construct and practicemy invention, I shall now describe a preferred embodiment thereof inconection with the accompanying drawings forming a part hereof.

,In the drawings: -Fi ure 1 is a dia aromatic view of a fluid supp ysystem emp oying an improved control embodying my invention;

' Fig. 2 is a detail view of one form of electric switch which may beemployed: there- .with- I 3 is a'detail view showing one side of Fig. 4is a to plan viewofthe switch taken 3 to illustrate the manner in whichboth sides-of the switch maybe connected in series with each other andin themoin practicallyany type of fluid supplysystemn Where safe,economical and automatic operation is desirable.

In the apparatus shown in the drawings, oil or liquid in the tank 5, orother et 21 may be may be located in any suitable manner in the system.It may comprise a gear pump driven by the motor of an oil distributor orblower commonly employed in oil burner apparatus.

Pump 7 and receptacle 8 are connected by means of a small tube 11, bywhich the oil enters receptacle 8 after having been drawn fromstorage'tank 5 by the pump. Ifind it desirable to seal the receptacleagainst the normal admission of air by suitably attaching its upper openend to the base 12 of pump 7. A suitable motor 14 is furnished to drivethe pump. The lower end of the receptacle may be closed. A pressureactuated element 15 is sealed to this lower end, but in communeeatingrelation with the interior of the receptacle so as to be responsive toand governed by the liquid head therein. Element 15 is illustrated inthe present disclosure as a bellows adapted to contract and expand asthe volume or pressure of the fluid varies. I find it desirable tolocate the switching device below the bellows, thereby positioning itout of the interior of the tank and away from the fluid containedtherein. Moreover, it may be placed in a. dirt proof housing 16,conveniently attached to the receptacle in order to protect the contactsof the switch against dirt and oil.

The switching device is preferably of a double actingtype to open themotor circuit when the bellows is either expanded or contracted to apredetermined distance. Hence, motor 14 may be stopped'when twoconditions obtain, viz when a maximum pressure or v olume of fluid iscontained within receptacle 8, and when a minimum pressure or volume offluid is present. To accomplish this fea-' ture, a double switch isvprovided. Both switches 18 and 19 are substantially the" same inconstruction and are of a quick make and break type so that the motorcircuit is instantly made or broken. Describing but one of theseswitches, preferably the one-designated 19 shown on the righthand sideof Fig. 2, a pivotally mounted plate 20- is carried by a bracket 21suitably secured in. housing 16, the plate having opposed laterallyextending lugs 22 loosel lyin in openings 23 in the sides of thebracket. 3 carbon contact 24 may be secured to the end ofthe plate byinterposingtherebetween suitable insulation, such as a lining of mica 25orthe like. Brackormed to extend outwardly to furnish a seat for a pairof contacts 26 and 27, also suitably insulated. These contacts areinserted in the motor circuit by means of screws 28, which pass throughbracket 21 and tacts 26 and 27.. This movement is obtained by theprovision of a downwardly projecting arm 29, on the base of bellows 15,cooperating with a spring 30. One end of this spring is fixed to bracket21, while the opposite end is fastened to plate 20 to move the sameupwardly when the spring is released by a lateral pin 31 carried by'arm29. Pin 31 may ride in a slot 32 formed in the side of bracket 21.

Hence, it will be noted that as bellows 15 contracts, which movementmight be the result of a normal flow of fluid out of tank 8 throu h pipe9 to burner 10, the fluid level will descend and the head or pressure onthe bellows will be lowered. When bellows 15 has undergone suflicientcontraction, the pin 31 allows spring 30 to flip bridging contact 24across contacts 26 and 27, thereby closing the motor circuit andallowing pump 7 to start operating, whereby to replenish the fluidwithdrawn from tank 8. However,

should the flow from the tank be at a greater rate than that which thepump will function to supply fluid to tank 8, the bellows furthercontracts and moves pin-31 upwardly until it engages a second spring 35to open the left hand switch 18. The motor circuit will'again' be brokenand the pump stopped.

When the fluid flows, in this manner, at a greater rate from tank 8 thanthat at which the pump will supply it thereto, an abnormal condition hasoccurred somewhere in the system. Such abnormal condition may be theresult of improper functionin of burner 10, or a leak or siphoningaction in the line.

In the event of normal operation, the level in tank 8 will rise if theburner is not consuming fluid as fast as it is supplied by pump Tomaintain the proper amount of fluid in the tank, the bellows is set toexpand when a predetermined high pressure exists in the tank. Suchexpansion will lower pin 31 to again engage spring 30 to o n switch 19.Thus, the proper amount 0 fluid will be maintained in tank 8.

In order to protect the system against siphoning when pump 7 is stopped,I prefer" to admit air into tank 8, hich tends to break the suction inpipe 9 and stop this siphoning. .Admission of air is controlled by avalve 35 at the side of tank 8. Valve 35 is normally spring pressed ainst its seat 36', but is fomd open by t e contraction of the "bellows.Whenthe system is at rest with the liquid level as shown in the drawings, bellows is expanded and switch 19 is open. The setting 11 of a si'honic action when pump 7 stops w lower e level, close switch 19, and thecontracting movement ofbellows-15 will pivotally swing a lever 36connected to one end of valve 35,'therebyopening the valve to admit airinto tank 8.

The rate of contraction of thebellows in ment may be such, of course, asnot to open valve during normal contraction of the bellows, by requiringa predetermined swing of lever 36 before it unseats'thevalve' It will beobserved, therefore, that ventmg of air with tank 8 is preferablydesirable when the pump is stopped as the result of an abnormalcondition, namely, a leak in line 9, or a: siphoning of the fluid afterpump 7 is stopped. A leak in line 9 immediately drains tank 8 of itsliquid so as to open switch 18. Hence the pump is instantly stopped andthe valve is unseated.

It will furthermore be evident that the system is designed to deliveroil to the burner under a sli ht pressure which results from the head 0oil in pipe!) and receptacle 8. Any breaking of or leak in the deliveryline will cause this pressure to fall and immediately cut off the s stemfrom any further pumping of oil. ence, siphoning of oil is preventedwhen a leak occurs, thereby assuring safety in the control of the ump,in

that, the entire contents of the b supply. tank 5 cannot be emptied intothe basement of the building.

' From the foregoing description, it will be observed that a novel formof automatic control, embodying the essential features of safetyrequired particularly in oil burnin apparatus, is disclosed which issimple and inexpensive, and which may be used universally'with any t peof pump, associated therewith, or provi ed apart from the pump in thesystem. Moreover, the control s apand circuit breaker mec the pressureof the liquid fuel in said'receptacle for opening the motor circuit whenthe rises or falls-beyond predetermined um r.

.parently capable of embodiment with pumps s i-pocket. formed in thelower part of said re-v other than the motor driventype.

Other modifications, arrangements and-embodiments of the resentinventionimay be obtained without ep rtingfrom the spirit and scope ofthe invention, 3

I .claim: .1. A liquid fuel feeding system including the combination ofa pump,"anelectric motor.

for driving said ump, a rece 'tacle for receiving the liquid elsuplplied y said pump, anism operated by 2. A fluid supplysysmnincluding the combination of a a receptaclefor receiving the fluidsupphed by and pump, and

pressureoperated means including a bellows communicating withtheinterior of said receptacle, said bellows being responsive to andgoverned by the pressure of the'fluid in said receptacle for stopping ofsaid pump when the pressure rises or falls beyond predetermined limits.

3. A liquid fuel feeding system including 4. A liquid fuel feedingsystem including the combination of a receptacle containing a varyingamountof liquid fuel therein, a delivery line leading from saidreceptacle, and means controlled by the pressure of the liquid fuel insaid receptacle for preventing a si-v phoning of liquid fuel from saidsource of supply to said receptacle.

5. A fluid supply system including the combination of a source ofsupply, a receptacle adapted to receive fluid therefrom, a deliver .pipeextending from said receptacle, an means res onsive to and governed by athe pressure of uid in said receptacle for preventing a siphoning of thefluid from said source of supply into said receptacle upon tbzeoccurrence of. a leak in said delivery pipe.

6. A liquid fuel feeding systemincluding the combination of a source ofsupply, a receptacle, a motor driven pump for supplying liquid fuel tosaid receptacle'from said source ofsupply, and electric switch mechanismoperated by the pressure of the liquid fuel in said rece tac le wherebyto close the motor circuit w enthe amount of liquid fuel therein variesbetween predetermined limits and to open the .circuit when the amount ofliquid fuel therein rises above or falls below said predeterminedlimits.

7.. A fluid supply systeria including the combination of a source ofsupply, a recep- -taele, a pump for supplyingfluid to said re-,ceptaclefrom said source of supply, and a variation of'the fluid-insaid receptacle for.

controlling said pump.

no a

8.- A fluid supply system including the andelect'rical means operated bysaid pres-' device for automatically opening the combination of a sourceof supply, a recepmotor circuit upon' an increase of pressure j to'amaximum and upon a decrease of pressuretoaminimum.

9. A fluid supply system including the combination of a source. ofsupply, a receptacle, an electric motor, a pump driven thereby forsupplying fluid to said receptacle from said source of supply, acontractible and expansible pressure operated element, and electricalcircuit breaking means adapted to open the motor circuit upon apredetermined contraction of said element and upon a predeterminedexpansion of said element.

10. A fluid supply system including the combination of a source ofsupply, a receptacle, an electric motor. a pump driven thereby forsupplying fluid to said rece tacle from said source of supply, acontracti le and expansible-pressure operated element, and twoelectrical switching devices, one of said switches opening the motorcircuit upon a predete rmined contraction of said element, the other ofsaid switches opening the motor circuit upona predetermined expansion ofsaid element. Y

11. A fluid supply system including the combination of a source ofsupply,- a receptacle, an electric motor, a pump driven thereby forsupplying fluid to said receptacle from said source of supply, apressure responsive device governed by the pressure in said receptacle,and two electrical switchin devices, one of said switches opening and cosing the motor circuit atoperating pressure for normal control of saidpump, the other of said switches opening the motor circuit at minimumpressure for safety control when an ab normal condition obtains.

12. A fluid supply system including the combination of a source ofsupply, an electric motor, a pump driven thereby, a pressure responsivedevice, and two electrical switching devices operated thereby, one ofsaid switches opening and closing the motor circuit for normal controlwhen normal operating pressure obtains; the other of said switchesopening the motor circuit at minimum pressure for safety control when anabnormal condition obtains. I

13. A fluid supply system including the combination of a pump, areceptacle for re-.

ceiving the fluid pumped, a delivery line communicating with saidreceptacle, means for starting and stopping the pump according to thepressure of the fluid in said receptacle, and anti-siphoning means forpreventing a siphonic action of the fluid through said delivery line.

14. A fluid supply system including the combinationof a pump, a pressureoperated element for starting and stopping said pump, and an air ventoperated upon the stopping of said pump .for preventing a siphonicaction of the fluid through the system.

15. A fluid supply system including the combination of a pump, areceptacle for receiving the fluid pumped, a delivery line communicatingwith said receptacle, means for starting and stopping the pump accordingto the pressure of the fluid 1n said receptacle,

and an air vent for said receptacle for preventing a siphonic action'ofthe fluid when the pump is stopped.

16. A fluid supply system including the combination of a pump, apressure 0 erated element for starting and stopping sai pump, andanti-siphoning means for preventing a siphonic action of the fluid whenthe pump is stoppped.

17. A fluid supply system including the combination of a pump, apressure operated element for starting and'stopping said pump, andanti-siphoning means controlled by said pressure element for preventinga siphonic action of the fluid when the pump is stopped.

18. A fluid supply system including the combination of a pump, areceptacle for receiving the fluid pumped, a delivery line leading fromsaid receptacle, provisions controlled by the pressure of the fluid insaid receptacle for starting and stopping said pump, and an air ventoperated by said pressure controlled provisions to prevent siphoning ofthe fluid through said delivery line when the pump is stopped.

19. In combination, a fluid pump, a pressure system supplied by saidpump, means for stopping said pump when predetermined maximum and mlmmumpressures obtain in said. system, and means operable thereby to vent airinto the s stem to prevent a siphonic action of the fluid in the system.

20. In combination, a fluid pump, a pressure system supplied by saidpump, means for stopping sai pump when predetermmedmaximum and minimumpressures obtain in said system, and means operable thereby to preventasiphonic act-ion of the fluid through said s stem when minimum pressureis reached.

. 21. A fluid supply s stem including the combination of a motor rivenpump, a receptacle for receiving the fluid pump, a contractible andexpansible element operably associated with said receptacle, an electricswitch controlled by said element to open the motor circuit when thepressure of the fluid in said receptacle reaches a minimum limit, and avalve adapted to be opened to vent air in said receptacle when the motorcircuit is opened by said switch.

22. A fluid supply system includingthe combination of a source ofsupply, a receptacle, means for delivering fluid from said source ofsupply to said receptacle, and means controlled by the pressure of thefluid in said receptacle for preventing a siphoning of the fluid fromsaid source of supply to said receptacle upon stopping of said fluiddelivery means.

In witness whereof, I have hereunto subscribed my name.

' LAWRENCE M. PERSONS.

